Data storage and removal in Language Understanding (LUIS) Azure AI services


LUIS will be retired on October 1st 2025 and starting April 1st 2023 you will not be able to create new LUIS resources. We recommend migrating your LUIS applications to conversational language understanding to benefit from continued product support and multilingual capabilities.

LUIS stores data encrypted in an Azure data store corresponding to the region specified by the key.

  • Data used to train the model such as entities, intents, and utterances will be saved in LUIS for the lifetime of the application. If an owner or contributor deletes the app, this data will be deleted with it. If an application hasn't been used in 90 days, it will be deleted.

  • Application authors can choose to enable logging on the utterances that are sent to a published application. If enabled, utterances will be saved for 30 days, and can be viewed by the application author. If logging isn't enabled when the application is published, this data is not stored.

Export and delete app

Users have full control over exporting and deleting the app.


Utterances can be stored in two different places.

  • During the authoring process, utterances are created and stored in the Intent. Utterances in intents are required for a successful LUIS app. Once the app is published and receives queries at the endpoint, the endpoint request's querystring, log=false, determines if the endpoint utterance is stored. If the endpoint is stored, it becomes part of the active learning utterances found in the Build section of the portal, in the Review endpoint utterances section.
  • When you review endpoint utterances, and add an utterance to an intent, the utterance is no longer stored as part of the endpoint utterances to be reviewed. It is added to the app's intents.

Delete example utterances from an intent

Delete example utterances used for training LUIS. If you delete an example utterance from your LUIS app, it is removed from the LUIS web service and is unavailable for export.

Delete utterances in review from active learning

You can delete utterances from the list of user utterances that LUIS suggests in the Review endpoint utterances page. Deleting utterances from this list prevents them from being suggested, but doesn't delete them from logs.

If you don't want active learning utterances, you can disable active learning. Disabling active learning also disables logging.

Disable logging utterances

Disabling active learning is disables logging.

Delete an account

If you are not migrated, you can delete your account and all your apps will be deleted along with their example utterances and logs. The data is retained for 90 days before the account and data are deleted permanently.

Deleting account is available from the Settings page. Select your account name in the top right navigation bar to get to the Settings page.

Delete an authoring resource

If you have migrated to an authoring resource, deleting the resource itself from the Azure portal will delete all your applications associated with that resource, along with their example utterances and logs. The data is retained for 90 days before it is deleted permanently.

To delete your resource, go to the Azure portal and select your LUIS authoring resource. Go to the Overview tab and select the Delete button on the top of the page. Then confirm your resource was deleted.

Data inactivity as an expired subscription

For the purposes of data retention and deletion, an inactive LUIS app may at Microsoft’s discretion be treated as an expired subscription. An app is considered inactive if it meets the following criteria for the last 90 days:

  • Has had no calls made to it.
  • Has not been modified.
  • Does not have a current key assigned to it.
  • Has not had a user sign in to it.

Next steps

Learn about exporting and deleting an app